I would suggest to make a plugin [button_in_article] -
that could provide a feature to insert in any CMS article specified item from e-shop.

Button could be with some parametrs, that might be choosen (hopefully at insertion phase)
to add to article
1. product (including short description, one picture, price, button <Buy>
2. product group or category (similar options)

May be some other options could be useful - forum participants could add more ideas.